1. Field of the Invention
This invention relates to couplings and in particular to quick connect-disconnect couplings for fluid conduit means such as fluid conduits, fluid containers, vent pipes, and structures associated with these items.
2. Prior Art Statement
It is known in the art to provide a quick connect-disconnect coupling for fluid conduit means comprising a coupler member adapter to be connected in such conduit means and having a first tubular outer end and a first sealing surface, an adapter member adapted to be connected in the conduit means and having a second tubular outer end and a second sealing surface with the second tubular end being adapted to be receive within the first tubular end, cam means for connecting and disconnecting the members comprising first cam means operatively associated with the first tubular end and second cam means operatively associated with the second tubular end, and seal means disposed between the sealing surfaces for providing a fluid-tight seal betwen the members with the cam means connected. Because a quick connect-disconnect coupling having these features is so well known, particular references showing such a coupling will not be presented herein.
However, a quick connect-disconnect coupling of the character mentioned is usually employed in a system which carries fluid under pressure; and, it is desirable that the connected members of the coupling not be disconnected while containing such fluid under pressure to prevent loss or escape of the fluid and to assure that the disconnected ends of the coupling members do not create a whipping action which might cause injury to personnel or damage adjoining articles. Further, in instances where the fluid under pressure is a hazardous fluid by being flammable, toxic, or the like, any escape thereof may pose other problems.
To prevent escape of loss of fluid should connected members of a couping be improperly disconnected it has been proposed to utilize special valve means between a coupler member and an adapter member of such a coupling. Typical couplings which utilize such special valve means are disclosed in U.S. Pat. Nos. 2,770,256 and 2,770,474.
It has also been proposed to provide a quick connect-disconnect coupling of the character mentioned which employs cam members which are spring urged to a closed position to prevent inadvertent disconnection thereof and of the associated coupling members of such coupling and as disclosed in U.S. Pat. Nos. 2,478,586 and 3,314,698, for example.
In addition, it has been proposed in a quick connect-disconnect coupling of the character mentioned to provide means for holding cam members associated with coupling members of the coupling in a locked position to prevent inadvertent disconnection of the coupling member. For example, U.S. Pat. No. 3,976,313 discloses detent balls for holding the cam members locked and U.S. Pat. No. 4,295,670 discloses a special removable wire pin for holding such cam members locked.
Finally, it has been proposed in U.S. Pat. No. 3,383,123 to utilize piston actuated rods to prevent disconnection of coupling members of a coupling in the event fluid under pressure is present in the conduit system using such coupling.
However, each of the above-described prior art quick connect-disconnect couplings has deficiencies because it either has no means provided to warn an operator and thereby prevent disconnection of the coupling in the event the coupling is in a system containing fluid under pressure, or it uses complex means to prevent loss of fluid, or it uses complex means to prevent disconnection of the coupling and these latter complex means do not allow the coupling to be operated in a normal manner.